Question

АЛГЕБРА помогите пожалуйста​

Answer 1

$a)2x^2=5x\\2x^2-5x=0\\x(2x-5)=0\\x_1=0\\\\2x-5=0\\2x=5\\x_2=\frac{5}{2} =2\frac{1}{2} \\\\b)0,49-x^2=0\\-x^2=-0,49\\x^2=0,49\\x=б\sqrt{49}\\ x=б0,7\\\\c)0,3x^2=7,5x\\0,3x^2-7,5x=0\\x(0,3x-7,5)=0\\x_1=0\\\\0,3x-7,5=0\\0,3x=7,5\\x=7,5:0,3\\x=25\\\\d)\frac{1}{4} x^2-25=0\\\\\frac{1}{4} x^2=25\\\\x^2=25:\frac{1}{4}\\\\x^2=100\\x=б\sqrt{100}\\x=б10$